The proposed FIRCA grant extends and expands a five-year U.S.-Chile collaborative study of the behavioral effects of iron deficiency anemia in infancy. The FIRCA award relates to Study II of the ongoing project. Study II will determine if there is a period of differential vulnerability to behavioral effects of iron deficiency anemia by characterizing alterations in affect, attention, activity, and neurophysiologic maturation of anemic infants who are identified at 6, 12, or 18 mos of age (n = 100 at each age). A comparison group of nonanemic infants at each age will provide baseline data for developmental progressions in children who maintain better iron status. Study II also focuses on ways to improve the behavior and development of infants who do develop iron deficiency anemia. Previous studies have shown that altered behavior and lower developmental test scores do not improve with iron therapy in most anemic infants and that behavioral differences are still apparent at school entry. This study will determine if providing family-based intervention in addition to iron therapy can correct the altered behavior and if intervention is more effective in the first or in the second year of life. Anemic and nonanemic infants at each age will be randomly assigned to receive iron therapy alone or iron therapy plus a home-based program of support for the child's development. Behavior and development will be compared before and after six and twelve months of intervention. A FIRCA award will accomplish three new goals: 1) to train Chilean co-investigators in behavioral analyses, 2) to allow the neurophysiologic laboratory in Chile to use improved equipment and techniques for studying neurophysiologic maturation in iron deficiency anemia, and 3) to permit Chilean co-investigators to modify the early intervention program so that it reflects the most current, thinking in the field and yet is culturally sensitive to Chile. The FIRCA grant would thus foster the development of Chilean collaborators so that they may achieve leadership roles in new areas and would allow INTA, the collaborating institution in Chile, to expand its longstanding function as a resource for nutrition related investigations throughout Latin America.